The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1887-03-19
Correspondence baltimore County Union.
SCIENTIFIC MIsCELLANY.
THE M1eHrIEsr OF WAVES.

SCIENTIFIC MISCEIL.tANY.
THE MIGHTIEsT OF WAVES.
The tidal wave, says Dana, differs from Ordi-
nary waves in many respects: inhaving an extra
terrestrial origin-the attraction of the moon and
sun--owing to which the ocean feels the impulse
to its bottom, and the wave is translation wave,
the movement being westward in consequence
of the earth's eastward revolution, and hence in
having the same rate of movement as the earth,
or 1000 miles an hour at the equator Chat is
movement in waye-motion, not in water; conse.
quently in having for the length of single wave
$4,000 miles, the ebb and flow occupying together
twelve hours. The Pacific is too narrow from
east to west to contain at once much over half of
the waye-curve, and the North Atlantic could hold
transversely but quarter of it. After leaving
the Pacific, its course is northwesterly in the In
dian Ocean, and the same also in the Atlantic
The height in the middle Atlantic is very SMALL
but as the depth diminishes on soundings, the
wave increases in elevation, and its translation
character becomes more and more appreciable.-
Still, at the prominent headlands of the continent
its height is only to 2 feet. Conveying coast
lines augment the tides height, that it becomes
feet at the entrance to New York Bay, Z feet at
Savannah, 10 feet at Boston, and 40 to 70 feet in
the narrow Bay of Fundy.
PRETTY EXPERIMENT.
An interesting method of recomposing white
light from the colors of the spectrum has been de-
scribed to the Paris Academy of Sciences by Mons.
Stroumbo. A prism is mounted upon an axis
raraIIeI 70 ;fs adoas and en- rIacad that tho sevan
prismatic rays are thrown on a white screen. The,
prism is then revolved, and when its rotation has
become sufficiently rapid the coors disappear, and
band of white light results.
AN ARCTIC GARDEN.
A curious geological phenomenon exists in
the vicinity of Behring's Strait At Elephant
Point, Kotzbue Sound, ridge two miles wide and
$50 feet high seems to be vast mass Office, thiny
covered with clay and vegetable mold. In this
soil birches, aders and Berry bearing plants grow
luxuriantly, with the stratum of perpetual ice as
the underlying rock within less than foot from
their roots.
TELEPHONE VS.. TELEGRAPH.
1t appears that communication by telephone to
great distances, though an interesting and won
derfu scientific achievement, is not likely to prove
commercially important. Estimates by DR..
Wietlisbach place the cost of telephone line 25O
miles long, over which speech is possible, at over
$4,000; and to make such line profitable it
must earn dollar minute, brief conversation
thus costing S. or $40. The telegraph works at
this distance at about tenth of the cost, and is
cheaper for all distances of more than 300 miles,
the economy being with the telephone below about
that limit.
FLATTEsT LAND.
Denmark, as is well known, is a remarkably
low country. 1t has long been supposed that its
highest land was hill 517 feet above sea-leyeI
but the surveys Of the past season show that there
are two higher points in the kin gdom-one reach
ing an elevation OF 500 feet and the other $40 feet.
A,HALF cENTURY's LOCOMOTIVE EVOLUTION.
In a recent address as President of the British
Institution of Civil Engineers, Mr. Edward Woods,
stated that the locomotives of fifty years ago con-
tanned the essential features of those of to- day. the
great improvements wrought having been in con-
structive detail. The modern engines possess at
least four times as great steaming power, coupled
with skiold weight. Compared with modern
locomotive the "Planet" type of 1892 to 1885 had
weight of y tons instead of As TONS a fire. crate
of square feet instead of 20 square feet and
heating surface of 800 square feet instead Of
400 square feet. An almost incredible economy
of fuel has been effected. About fifty years ago
, for instance, one railway line consumed IL 900
tons per annum, while few years later g. 100 tons
suficed for a considerably greater traffic. The
tractive power has been increased fvefold, and all
gradients up to in 20 are now readily surmounted
Ordinary speeds have considerably increased, yet
express and special trains run but little faster
In track-laying, mistake of the early engineers
was the use of stone sleepers, making a road so
rigid that rails were often broken. Steel has su-
perseded iron for rails, at present cost of only
half that of the iron rails in 1870, while the dura-
bility is about three times as great. -.
JUPITER RED-HoT?
member of the Royal Society of Tasmania
fnds that, as compared with Mars, Jupiter sur
ought to be if all its light is reflected sunshine
and as compared with the moon, about thirteen
times. That the brilliancy was remarkable has
long been known, and the theory of this observer
that the giant planet of our system has not yet so
cooled as to cease to be sef-lumincus, is BY no
means new. more generally accepted expla-
nation, however, is that Jupiter is covered with
very highly reflective material which absorbs
much less solar light than Mars and the moon.
MISCELLANEOUS.
The death rate of England is decreasing, and
$50 people are added yearly to each 10000. At
the present rate OF increase, according to DR.. M.
Tidy the country Stipulation twenty generations
hence. willIb q, zoo, OO0, 000 or enough to fill
twenty earths with the present density Of popula-
ton.
Among the many curious and interesting works
OF the largest library in the world, at Paris is
Chinese chart of the heavens, made about 900 B.
@. In this chart AGO stars are correctly inserted
as corroborated by the observations Of modern
astronomers.
Amarine alga of Arctic regions grows at tenn
perature far below zero, and its spores disappear
at higher temperatures. 1t thus appears that in
tense cold is necessary to the existence of some
forms of vegetable life, together with extreme dry
ness, and this class of plants probably, includes
the cryptogams of red snow. = e" - E - sia
peculiar black paper, made from the bark of
certain trees serves the purpose of states in Siam
and Burmah, the writing being erased by means
of betel leaves instead of with a sponpe 'ff39